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From: dpbaudra@ihlpe.ATT.COM (Braune)
Newsgroups: comp.sys.att
Subject: Re: interleave and disk performance
Message-ID: <2147@ihlpe.ATT.COM>
Date: Wed, 7-Oct-87 12:05:05 EDT
Article-I.D.: ihlpe.2147
Posted: Wed Oct  7 12:05:05 1987
Date-Received: Sat, 10-Oct-87 10:06:59 EDT
References: <2310@sphinx.uchicago.edu> <710@neoucom.UUCP> <2119@ihlpe.ATT.COM> <6699@sgi.SGI.COM>
Reply-To: dpbaudra@ihlpe.UUCP (452is-Braune,D.P.)
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 39

In article <6699@sgi.SGI.COM> gsk@khaki writes:
>can anybody tell me what interleave (and step rate?) to use with
>the DTC 5150BX controller (the one AT&T OEMs from DTC) and an ST225
>on my 6300 running DOS 3.2 ?

A colleague has expeience with the following in a PC6300:
		ST225/DTC5150BX     IL=5
		ST238/Adaptec RLL   IL=5

Proper step rate is still an issue however a Seagate book now in my possession
says ST225/238 disks can accept step rate pulses from 5usec to 200usec. First
try would be to shoot for anything close to (but equal to or greater than 
5usec). 

>once i know what parameters to use, how do i do a low-level format with them?
>(the DTC ROM formatting routines don't ask you for any parameter values)

I'm told that some people have called AT&T and received a disk with
a pgm called LOWFORM.EXE that is menu driven and will permit such parameter
control.

>data for other drives with the above system are also of interest to me,
>since i'm thinking about adding another drive to my system.

		Miniscribe 3425/WD RLL      IL=7

>while we're on the subject of disk performance, has anyone compared
>various controllers against each other w.r.t. performance?
>is anyone successfully using controllers that do whole-track buffering,
>caching, etc?
>George S. Kong,  Silicon Graphics, Inc.,  (415)962-3281
>gsk@sgi.com
>...{decwrl,allegra,sun,adobe,ucbvax,pyramid,ames}!sgi!gsk

I have no data but would also like to see some.

Dave Braune
AT&T 
ihnp4!ihlpe!dpbaudra